Combination blasting method and means



Jan. 12 1926.

D. FERRELL El AL COMBINATICN BLASTING METHODAND MEANS Filed March 16, 1925 efzi meZZ, l wwf 14K/fami@ Patented Jan. 12, 1926.

STATES PATENT OFFICE.

COMBINATION BLASTING METHOD AND MEANS.

Application led March 16, 1925. Serial No. 15,728.

i To all whom 'it may concern.'

Be it known that we, DENT FERRELL, and ARTHUR W. HELMHoLTz, citizens of the United States, residing, respectively, at Harrisburg, in the county of Saline and State of Illinois, and at Harrisburg, in the county of Saline and State of Illinois, have jointly invented certain new and useful Improvements in Combination Blasting Methods and Means, of which the following is a specification.

This invention relates to anew and im! proved method and apparatus for blasting and more particularly, to a method and apparatus adapted to combine mechanical means and electrical or chemical means for the purpose of producing a blasting pressure.

In our pending application, Serial No. 744,184, filed October 17, 1924, We have disclosed a blasting method and means which utilizes mechanical pressure. In our copending application, Serial No. 8328, tiled' February 11, 1925 jointly w-ithJohn H. Crawford, we have disclosed a method and apparatus for blasting which utilizes electrical or chemical heat or both to gasify a :Huid to thereby develop a blasting pressure.

The present application comprises a method and apparatus in which both mechanical pressure and the electrical or chemical means, or both means, are used.

In our application, Serial No. 8328, we disclosed a use ot'v a container which was filled with a iuid, preferably carbon dioxide at lling stations situated at convenient points in the shaft bottoms in coal mines, for example, and the cartridges, when filled with the blasting medium at orslightly below the critical pressure and temperature, were distributed to the various points of use. c

Since the cartridges are thus lilled with the fluid blasting medium to a rather high pressure, as for example, 1,900 pounds per square inch, there is the possibility of fear being instilled into the minds of the men Working with the cartridge that the devices are not stable, but are dangerousand antagonism to their use is thereforexa possibility. In reality the cartridges Aare very drill hole to the valve 15.

stable under normal ,conditions and any possibility of permature explosions from ordinary causes is very remote, but the objections of the men working with them must be considered.

To eliminate the possibility of such objections, the apparatus and method of the present applicationpdo not till the cartridges With fluid under pressure unt-il the cartridges are tamped in place in the drill holes. The cartridges are, therefore, handled and transported without containing any material above at-mospheric pressure.

It is an object of the present invention to provide a new and improved method and apparatus for blasting whereby all the elements of the apparatus may be handled and transported Without danger to the operating personnel.

It is an additional object to provide a means and method of this character adapted to blast without the formation of any objectionable or dangerous gases or fumes.

It is also an object to provide a means and method adapted to be carried out by apparatus which is simple in design and construction and the' replaceable portions of which are inexpensive.

Other and further objects will appear as the description proceeds.

We have illustrated in the accompanying drawings certain forms of apparatus adapted for carrying out the method described herein.

In the drawings Figure 1 is an elevation showing the apparatus in place in the drill hole;

Figure 2 is a cross section of one form ot cartridge, and

Figure 3 is a view of another form of cartridge.

Referring rst to Figure. 1, the cartridge 11 is placed in the drill hole 12 and the hole is lled with the tamped material 13 as is customary in ordinary blasting. The pipe 14 leads from the cartridge 11 out of the From the valve 15 the pipe 16 leads to the pump 17. The pump 17 is connected to the fiuid tank 18 by pipe 19. The source of electricity has been shown as the blasting machine 2U 4 26 by means of the outer collar 28.

which is connected by wire 21 with the outer shellof the cartridge 11 and by the wire 22 with the pipe 14 which latter is connectd to I.the interior elements of the cartridge.

The type of cartridge shown in Figure 2 comprises the shell 25 which is internally threaded at both ends. At the right end of the cartridge, the collar 26 is threaded into the casing or .shell and the rupturable disc 27 is retained in place against the colr e collar 26l may force 'a packing ring 29 against the face of the disc 27. The disc 27 is weakened by a circular groove 30,

' which will cause the central portion of the provided withthe conductor 38- adapted to disc t0 blow out at predetermined pressure. The perforated tubular conductor 31 has its right end supported upon the boss 32 of the disc 27. The left end of the conductor 31/is supported upon the boss 33 of the plugVV 34. Thisplug 34 is supported in the end of the shell'25 by the colla-r 35 which is threaded into the end of the shell. The plug 34 is insulated from the collar 35 by the insulating layer 36. The nut 37 is threaded upon the outer end of the plug 34 and retains the elements in place. The nutv 34 is be connected in velectrical circuit. The casing 25 is'provided with a similar connector 39. The plug v34 is provided with a central bore 40 which communicates with the interior of the shell 25 through thel bores 41.

. the exception of the heat producing element.

Instead of the perforated fusible and vaporizable conductor 31.shown in Figure 2, the form of Figure 3 includes a tubular member 44 which contains an inflammable subsance 45 and the ijusible conductors 46. The tube 44 is preferably of water-prooi` material and the inflammable material 45 Urn/ay be common black powder. The fusible element 46 is in electrical contact with the disc 27 and the plug 34. This element 46 may merely fuse and ignite the inflammable material, or it may be vaporized and in itself assist directly to transmitting heat to the fluid in the cartridge.

`In th-e operation of our method and apparatus the cartridges are equipped at the -Y point of preparation with the discs 27 adaptthis time.

l. ed to rupture at th desired blasting pressure.

The desired orm of heat producing means is also installed in thexcartridge at The disc 27 and plug 34 are screwed in very tightlyso as to maintain the container gas tight .even under very high internal pressure. The cartridges are then transported to the working place or rooms where they are to be used. The cartridges are rugged and strong in construction and contain no explosive and may thus be handled with perfect conidence and security by the men working with them.

Each room or` place where blasting is to be done will be provided with a' smally portable pumping plant, the container for carbon dioxide or other blasting medium of sufcient volume for the shots to be made and a battery or generator of suitable size to furnish the current and Voltage necessary to explode the metallic element, if this form of electrical heating means is used, or to ignite the charge ofl inammablematerial or explosive if such means of heat production is used.

When the cartridges are toy be used the crew will attach the electric wires to the connectors 38 and 39 and screw the pipe 14 in place and place the cartridge in the bottom of the drill hole and tamp it in place. It will be noted that the pipe 14,is in electrical connection with the plug 34 and conthe pressure indicator 47 shows the desired.

pressure. The valve 15 is then closed and the pumping stopped. The pressure in thel cartridge may be brought to any desired pressure below that of the rupturing point of the'disc 27-in the cartridgeA In'all forms of our invention we prefer to fill the cartridge with carbon dioxide at the critical pressure and temperature which assure us the contents of the cartridge will be in the liquid. phase. This is essential in our application previously referred to in which we use the electrical or chemical rise suiiicient to rupture the disc as this particular device is filled at the filling station and the medium must be liquid in order to produce the maximum` effect. In the other pending application and in the present but make the pressure vary, always however, retaining the liquid phase in order to make use @of the large ratio of expansion available when the medium changes to the gaseous case we still hold t0 the critical temperature,

liquid carbonV dioxide is intensely heatea and the pressure almost instantaneously raised to a value above the rupturing strength of the disc. The central portion of the latter gives Way and the now gasified carbon dioxide rushes violently out into the drill hole and breaks down the coal, as a result of the high pressure as Well as the great expansion effect.

It is obvious that a further advantage ensues as a result of creating a pressure of liquid carbon dioxide in the cartridge, by mechanical means, to a point Within a suitable degree of safety. For example, suppose that a disc were chosen which required 6,000 pounds per square inch to rupture. The cartridge would ordinarily be filled with medium to about 1,100 pounds per square inch and dependence would be placed upon the application of artificial heat to raise the pressure to the value, 6,000 pounds per square inch. This can, of course, be done by suitable current or chemical charge, but with the pump the static pressure could be raised to a value of say, 5,000 pounds per square inch and the final pressure increment is then gotten by means of artificial heat application. The quantity of heat necessary to raise the mass of medium from a pressure of 5,000 pounds to 6,000 pounds and slightly above, is naturally less than that required to raise the pressure from 1,100 pounds to a value of 6,000 pounds and more,'even taking into consideration the fact that there will be a much larger mass of gas at 5,000 pounds pressure than there is at 1,100 pounds. Therefore, smaller current is required in this case or smaller charges of explosive can be used. The cost of pumping must, of course, be charged against this method, but the ele- -ment of added feelings of safety, more than compensate for the extra costs.

.While We have described one preferred forni of construction and of carrying out our method, we contemplate such changes and modifications as come within the spirit and scope of the accompanying claims.

`We claim: v

1. The method of blasting which comprises inserting into a drill hole a closed container, connecting the container to a source of fluid supply, forcing fluid into the closed container under pressure, and applying to Said fluid a gasif'ying heat, the gasification producing a pressure sufficient to rupture a wall of the container.

2. The method of blasting which comprises inserting into a drill hole a closed container, connecting the container to a source of supply of a compressible fluid not a liquid at atmospheric pressure and temperature, forcing said fluid-into the container under pressure sufficient to maintain the fluid in the liquid state, and applying to said fluid a gasif'ying heat, the gasification producing a pressure sufficient to rupture a wall of the container.

3. The method of blasting which comprises inserting into a drill hole a closed container, connecting the container to a source of supply of carbon dioxide, forcing the carbon dioxide into the container under pressure sufficient to maintain it in the liquid state and applying to said carbon dioxide a gasifying heat, the gasification producing a pressure sufficient to rupture a Wall of the container.

el. The method of blasting which Comprises inserting into a drill hole ad closed container, connecting the container to a source of fluid supply, forcing fluid into the closed container under pressure, and applying to said fluid a gasifying heat by means of the vaporization of an electrical conductor in the container, the gasification producing a pressure suflicient to rupture a Wall of the container.

5. The method of blasting which comprises inserting into a drill hole a closed container, connecting the container to a s ource of supply of compressible fluid not a liquid at atmospheric pressure and temperature, forcing said fluid into the container under pressure sufficient to maintain the fluid in the liquid state, and applying to said fluid a gasifying heat by means of the vaporization of an electrical conductor in the container, the gasification producing a pressure Sufficient to rupture a Wall of the container.

6. The method of blasting which com- 'Yprises inserting into a drill hole a closed container, connecting the container to a source of supply of carbon dioxide, forcing the carbon dioxide into the container under pressure suflicient to maintain it in the liquid State and applying to said carbon dioxide a gasifying heat by means of the vaporization of an electrical conductor in the container7 the gasification producing pressure suffici-entto rupture a Wall of the container.

7. rlhe method of blasting which comprises inserting into adrill hole a closed container, connecting the container to a source of fluid supply, forcing fluid into the closed container under pressure, and applyin to said fluid a gasifying heat by'means o the vaporization of an electrical conductor and the rapid combustion of material adapted to liberate heat in the container, the gasification producing a pressure suflicient to rupture a Wall of the container.

8. Apparatus for blasting comprising a rigid container, means in said container rigid container, a removable wall in said container adapted to rupture at a predetermined pressure, means in said container adapted to liberate heat, a source of fluid container, and means adapted to supply elecsupply, and means adapted to force said ticity to the electrical means in the con- 10 fluid under pressure into the container. tainer. A

l0. Apparatus for blasting comprising a Signed at Harrisburg, Illinois, this 10th 5 rigid container, electrical means in the conday of March, 1925.

tainer adapted to cause the liberation of heat, a source of fluid supply, means adapted DENT FERRELL. to force said fluid vunder pressure into the ARTHUR W. HELMHOLTZ. 

